If you want to challenge the story, present other sources with the other view point. Don't go after one messenger, and use prior bad or not-bad acts to cast the journalist in a negative light. That's very not helpful.
Yes yes, a series of bad journalism can show a pattern and that's how prosecutors go after organized crimes and serial killers. But don't pretend there are bias and unbias journalists. Everyone has a bias. Most of what we see is propaganda and not news.